CN107013275B

CN107013275B - Roller tappet and method for producing same

Info

Publication number: CN107013275B
Application number: CN201710059857.4A
Authority: CN
Inventors: 冈秀树
Original assignee: Otics Corp
Current assignee: Otics Corp
Priority date: 2016-01-28
Filing date: 2017-01-24
Publication date: 2020-07-07
Anticipated expiration: 2037-01-24
Also published as: JP2017133423A; US10167833B2; CN107013275A; EP3199795B1; JP6571019B2; US20170218905A1; EP3199795A1

Abstract

The invention provides a roller tappet capable of inhibiting increase of manufacturing cost and a manufacturing method thereof. A roller tappet (10) is provided with: a tappet main body (11) having a cylindrical peripheral wall (12), and sliding surfaces (21A, 21B) on the outer periphery of the peripheral wall (12) sliding on an inner wall (62) of a cylinder (61); and a roller (18) which is rotatably disposed on the tappet body (11) via the shaft member (16) and which is in contact with the cam (90). The tappet body (11) has a rotation stop portion (22) in which a part of the peripheral wall (12) protrudes outward, and an opening portion (26) that is open in the peripheral wall (12) at a position on the opposite side of the rotation stop portion (22) in the radial direction, such that the rotation stop portion (22) faces the opening portion.

Description

Roller tappet and method for producing same

Technical Field

The present invention relates to a roller tappet and a method for manufacturing the same.

Background

The roller tappet disclosed in patent document 1 includes: a tappet body having a sliding surface that slides on an inner wall of a cylinder; and a roller rotatably attached to the tappet body via a shaft support pin and in contact with the cam. The tappet body has a rotation stopper protruding outward, and has a front sliding surface on a front side of the rotation stopper and a rear sliding surface on a rear side thereof in a sliding direction. The rotation stopper is formed by pressing the punch against the inner peripheral surface of the peripheral wall of the tappet body to bend the tappet body outward.

According to the structure of patent document 1, the rigidity of the tappet body can be improved, and the front-rear length of the sliding surface can be ensured to be long, so that the axial wobble (cock) of the roller tappet with respect to the inner wall of the cylinder can be suppressed.

Prior art documents

Patent document

Patent document 1: japanese patent laid-open publication No. 2014-1706

Disclosure of Invention

Problems to be solved by the invention

However, in the case of the roller lifter described above, when the rotation stopper is formed, the moving direction of the punch is defined such that the punch is inserted into the peripheral wall of the lifter body in the axial direction, and after the direction of the inserted punch is changed to the radial direction in the peripheral wall, a part of the peripheral wall is pressed. Therefore, there is a problem that the metal mold structure is complicated, and the manufacturing cost is increased.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a roller lifter and a method for manufacturing the same, which can suppress an increase in manufacturing cost.

Means for solving the problems

The present invention is a roller tappet, including: a tappet body having a cylindrical peripheral wall, a sliding surface of an outer periphery of the peripheral wall sliding on an inner wall of a cylinder; and a roller rotatably disposed on the tappet body via a shaft member and in contact with the cam, wherein the tappet body has a rotation stopper portion in which a part of the peripheral wall protrudes outward, and the roller tappet is characterized in that the tappet body further has an opening portion at a portion of the peripheral wall opposite to the rotation stopper portion in a radial direction, and the opening portion is opened so that the rotation stopper portion faces the opening portion.

In the method of manufacturing the roller lifter, the punch member for forming the rotation stopper portion, which moves in the radial direction, penetrates the opening portion and enters the inside of the peripheral wall, and pushes out a part of the peripheral wall to the outside.

Effects of the invention

Since the rotation stopper can be formed by the punch member passing through the opening from the outside of the peripheral wall and moving in the radial direction, it is not necessary to adopt a complicated die structure, and an increase in manufacturing cost can be suppressed. Further, the rotation stopper can be quickly formed, and productivity can be improved.

Drawings

Fig. 1 is a sectional view of a fuel supply pump including a roller tappet according to a first embodiment of the present invention.

Fig. 2 is a cross-sectional view of a roller tappet.

Fig. 3 is a sectional view of the roller lifter as viewed from below.

Fig. 4 is a sectional view for explaining a step of forming the opening portion.

Fig. 5 is a sectional view for explaining a step of forming the rotation stopper.

Fig. 6 is a sectional view of a roller tappet according to a second embodiment of the present invention.

Detailed Description

< example one >

Embodiment 1 of the present invention will be explained with reference to fig. 1 to 5. The roller tappet 10 according to the first embodiment exemplifies a pump tappet provided in a fuel supply pump 60 of an internal combustion engine of an automobile. The roller lifter 10 includes a lifter body 11 that is slidable on an inner wall 62 of a cylinder 61 of a fuel supply pump 60.

As shown in fig. 2, the tappet body 11 has a peripheral wall 12 and a partition wall 13. The peripheral wall 12 is substantially cylindrical and is open in the vertical direction. The partition wall 13 is connected to the inner circumferential surface of the circumferential wall 12 at a midpoint in the vertical direction. The inside of the peripheral wall 12 is closed by a partition wall 13 and is divided vertically by the partition wall 13.

The peripheral wall 12 has a pair of opposing wall portions 14 on a lower half. As shown in fig. 3, the two opposing wall portions 14 are brought together from the peripheral portion and are disposed to face each other in a substantially parallel manner. The two opposing wall portions 14 have insertion holes 15 that coaxially penetrate in the radial direction. A shaft member 16 is bridged between the two opposing wall portions 14 in the radial direction. Both end portions of the shaft member 16 are inserted into the insertion holes 15 and are caulked and fixed to the two opposing wall portions 14.

As shown in fig. 1, the shaft member 16 rotatably supports the rollers 18 via bearings 17. The outer peripheral surface of the roller 18 contacts the cam 90. The cam 90 is provided on a cam shaft 91 parallel to the shaft member 16. The lower end of the roller 18 is disposed so as to be exposed downward from the lower end of the tappet body 11.

As shown in fig. 2, the outer peripheral surface of the peripheral wall 12 has a recess 19 and sliding

surfaces

21A, 21B. The recess 19 is reduced in diameter over the entire circumference, and is located at a lower portion of the circumferential wall 12 including the two opposing wall portions 14. The

sliding surfaces

21A, 21B are disposed on both upper and lower sides (both front and rear ends in the sliding direction) of the recess 19 on the outer peripheral surface of the peripheral wall 12. The

sliding surfaces

21A and 21B of the peripheral wall 12 are slidable on the inner wall 62 of the cylinder 61. Here, the upper and lower regions of the upper sliding surface 21A are sufficiently larger than the lower sliding surface 21B.

The peripheral wall 12 has a rotation stopper 22 at a position corresponding to the recess 19. The rotation stopper 22 is cantilevered from the root to the tip in a diagonally upward direction. The rotation stopper 22 is formed by pushing outward a plate piece portion 24 (see fig. 4) between substantially angular U-shaped notches 23 formed in the recess 19 by a punch member 50 for forming a rotation stopper, which will be described later. The peripheral wall 12 is also formed with a through hole 25 together with the rotation stopper 22. The distal end of the rotation stopper 22 is located radially outward of the

sliding surfaces

21A and 21B.

The peripheral wall 12 has an opening 26 at a position on the opposite side of the recess 19 in the radial direction of the rotation stopper 22. In other words, the rotation stopper 22 and the opening 26 are disposed on both sides of the circumferential wall 12 in the radial direction with respect to the axial center, and more specifically, the rotation stopper 22 and the opening 26 are disposed on both ends of the circumferential wall 12 in the direction substantially perpendicular to the direction in which the two opposing wall portions 14 oppose each other (the axial direction of the shaft member 16). When the rotation stopper 22 is projected in the radial direction on the peripheral wall 12, the entire projection area of the rotation stopper 22 is contained inside the opening 26. The opening 26 penetrates a part of the peripheral wall 12 in the radial direction, and opens to the inner peripheral surface and the outer peripheral surface (the recess 19) of the peripheral wall 12. The opening 26 has a rectangular cross-sectional shape corresponding to the projected shape of the rotation stopper 22, and is configured as a ring-shaped opening that is continuous over the entire circumference.

Next, respective manufacturing methods of the opening portion 26 and the rotation stopper portion 22 in the roller lifter 10 will be described.

As shown in fig. 4, first, the opening 26 is formed using a punch member 80 for opening formation. Before punching the punch member 80, the receiving die 70 is inserted into the peripheral wall 12 from below. The receiving die 70 has a window portion 71 at a portion corresponding to the formation position of the opening portion 26. In addition, the receiving die 70 is provided so that, in a state of being inserted into the peripheral wall 12, the portions other than the window portion 71 abut along the inner peripheral surface of the peripheral wall 12.

Next, the punch member 80 for opening portion formation penetrates the peripheral wall 12 and radially presses the peripheral wall 12. The punch member 80 has a rod portion 81 extending in the radial direction and having a cross-sectional shape corresponding to the opening portion 26. Further, the tip of the rod 81 is formed to be sharp. The opening 26 is punched out by moving the punch member 80 in the radial direction and piercing the tip end of the rod 81 through the opposing portion of the peripheral wall 12, thereby penetrating the rod 81 through the peripheral wall 12. In this case, the rod portion 81 is inserted into the window portion 71 of the receiving die 70 and guided. Further, the receiving die 70 can suppress the occurrence of burrs on the inner peripheral edge of the opening 26, and can prevent the deformation of the peripheral wall 12. Before the punch member 80 is pressed, a cut edge along the outer periphery of the opening 26 may be formed in advance in the peripheral wall 12.

Next, as shown in fig. 5, the rotation stopper 22 is molded using a punch member 50 for molding the rotation stopper. Here, a substantially angular U-shaped notch 23 is formed in advance in the peripheral wall 12 along the outer edge of the rotation stopper 22. The punch member 50 has a rod-like portion 51 elongated in the radial direction. The rod-shaped portion 51 has a pressing surface 52 inclined downward at a distal end portion thereof corresponding to the rotation stopper 22.

The punch member 50 is moved in the radial direction, and the rod-like portion 51 is inserted into the peripheral wall 12 through the opening 26. At this time, the rod-like portions 51 are arranged along the radial direction so as to extend to the inside and outside of the peripheral wall 12 through the opening 26. From this state, the tip end portion of the rod-like portion 51 is brought into contact with the sheet portion 24 between the notches 23 of the peripheral wall 12 from the inside, and is deformed so that the tip end portion of the rod-like portion 51 pushes down the sheet portion 24 of the peripheral wall 12 by further radial movement of the punch member 50. Thereby, the through hole 25 is opened, and the rotation stopper 22 is formed by bending so as to be inclined along the pressing surface 52 of the rod-shaped portion 51. The rotation stopper 22 may be configured to be supported from the back by a support die, not shown, when pressed and tilted by the punch member 50.

However, in the above case, it is necessary to use two types of

punch members

50 and 80 for forming the rotation stopper and the opening. In contrast, the opening 26 and the rotation stopper 22 may be formed at a time by moving a common punch member in the radial direction. Further, if the tappet body 11 is a cast product, the opening 26 may be formed simultaneously with the casting of the peripheral wall 12.

Next, the structure and operation of the fuel supply pump 60 including the roller tappet 10 will be described. As shown in fig. 1, the cylinder 61 has a slide hole 63 extending in the up-down direction. An inner wall 62 of the cylinder 61 is formed on an inner peripheral surface of the slide hole 63. The upper end of the slide hole 63 is closed by the block portion 64. The block portion 64 has a through hole 66, and an engagement member 65 described later is slidably inserted through the through hole 66. Further, the cylinder 61 has a rotation stop groove 67 extending in the up-down direction along the slide hole 63 (inner wall 62). The lower end of the rotation stopping groove 67 is opened.

An engagement member 65 such as a plunger, a spring member 68 such as a coil spring, and a stopper 69 are housed in an upper portion of the tappet body 11. The engaging member 65 is fixed to the stopper 69, and the stopper 69 is supported by the partition wall 13. The stopper 69 faces the block portion 64 of the cylinder 61, and the spring member 68 is elastically sandwiched between the block portion 64 and the stopper 69.

When the cam 90 rotates in accordance with the driving of the engine, the tappet body 11 reciprocates in the vertical direction by a stroke corresponding to the lift amount of the cam 90. The engagement member 65 reciprocates in the vertical direction together with the tappet body 11, and hydraulic oil is pressure-fed from a pressure chamber, not shown, located above the engagement member 65. During this time, the sliding

surfaces

21A and 21B of the tappet body 11 slide on the inner wall 62 of the cylinder 61, and the detent portion 22 is displaced in the vertical direction while entering the detent groove 67. In this way, by maintaining the state in which the detent portion 22 enters the detent groove 67, the tappet body 11 is prevented from rotating around the axis inside the slide hole 63.

In the first embodiment, since the peripheral wall 12 of the tappet body 11 has the respective upper and lower sliding

surfaces

21A and 21B on the outer peripheral surface, a long sliding area in the vertical direction can be ensured, and occurrence of shaft shake (cocking) of the tappet body 11 can be suppressed.

Further, since the peripheral wall 12 of the tappet body 11 has the recessed portion 19 between the upper and lower sliding

surfaces

21A, 21B, the recessed portion 19 is separated from the inner wall 62 of the cylinder 61, so that the inner wall 62 does not substantially engage with the opening 26 opened in the recessed portion 19, and the smoothness of the reciprocating operation of the roller tappet 10 is ensured.

Further, according to the first embodiment, since the rotation stopper 22 can be easily formed by the punch member 50 for forming the rotation stopper passing through the opening 26 from the outside of the peripheral wall 12 and moving in the radial direction, it is not necessary to adopt a complicated die structure, and an increase in manufacturing cost can be suppressed. Further, the rotation stopper 22 can be molded quickly, and productivity can be improved.

Further, since the opening 26 is formed as a ring-shaped opening continuous over the entire circumference and is not opened to both the upper and lower ends (both the front and rear ends in the sliding direction) of the peripheral wall 12, for example, at the time of finishing, the sliding

surfaces

21A, 21B and the like at both the upper and lower ends of the peripheral wall 12 can be engaged with the grindstone or the die holder template without hindrance and the tappet body 11 can be rotated, and thus the grinding process can be smoothly performed.

Further, when the rotation stopper 22 is projected in the radial direction on the peripheral wall 12, the entire projection area of the rotation stopper 22 is contained inside the opening 26, and therefore the rotation stopper 22 can be formed without hindrance by the rod-like punch member 50 penetrating the peripheral wall 12.

< example two >

Fig. 6 shows a roller tappet 10A according to a second embodiment. The form of the rotation stopper 22A of the second embodiment is different from that of the first embodiment.

The rotation stopper 22A is configured such that a part of the peripheral wall 12 bulges outward from the periphery. Specifically, the rotation stopper 22A is formed so as to be bulged so that the entire circumference is continuous with a part of the circumferential wall 12 without being cut from the circumference. When the rotation stopper 22A is formed, the tip end surface of a punch member for forming the rotation stopper, not shown, presses the inner peripheral surface of the peripheral wall 12, and the corresponding portion of the peripheral wall 12 bulges outward along the tip end surface of the punch member. In this case, the punch member is configured not to open the peripheral wall 12, and unlike the first embodiment, the through hole 25 is not formed in the peripheral wall 12.

In the case of the second embodiment, as in the first embodiment, the rotation stopper 22A is formed by passing a punch member for forming the rotation stopper through the opening 26 and moving the punch member in the radial direction so as to be continuously bulged from a part of the peripheral wall 12. Therefore, the rotation stopper 22A has a curved contour and a shape without an edge, and the inner wall 62 of the cylinder 61 can be prevented from being damaged by the rotation stopper 22A. Further, the rigidity of the rotation stopper 22A can be improved.

< other embodiments >

Other embodiments will be briefly described below.

(1) In the case of the first embodiment, the rotation stopper may be formed simultaneously while forming a notch in the peripheral wall by the tip end portion of the punch member for forming the rotation stopper, instead of forming the notch in the peripheral wall.

(2) The rotation stopper and the opening may be provided at an upper portion of the peripheral wall (above the partition wall in the vertical direction).

(3) The opening may have a non-annular shape that opens to the upper end or the lower end of the peripheral wall.

(4) The rotation stopper may be in a form in which both ends connected to a part of the peripheral wall in any one of the vertical direction and the horizontal direction are fixed.

(5) The present invention can be applied to a valve lifter that abuts against a valve stem (engagement member) of a valve that can open and close an intake port and an exhaust port of an engine.

Description of the symbols

10. 10a … roller tappets;

11 … tappet bodies;

12 … peripheral wall;

16 … shaft member;

18 … roller;

19 … recess;

21A, 21B … sliding surface;

22. 22a … rotation stop part;

26 … opening part;

a punch member for forming the 50 … rotation stopper;

a 61 … cylinder;

62 … inner wall;

80 … a punch member for forming the opening;

90 … cam.

Claims

1. A roller tappet is provided with:

a tappet body having a cylindrical peripheral wall, a sliding surface of an outer periphery of the peripheral wall sliding on an inner wall of a cylinder;

a roller rotatably disposed on the tappet body via a shaft member and in contact with the cam,

the tappet body has a rotation stopper in which a part of the peripheral wall protrudes outward,

the roller tappet is characterized in that it is,

the tappet body further includes an opening portion at a portion of the circumferential wall on a side opposite to a radial direction of the rotation stopper, the opening portion being opened so that the rotation stopper faces the opening portion,

the opening portion has a rectangular cross-sectional shape corresponding to a radially projected shape of the rotation stopper portion.

2. The roller lifter of claim 1, wherein,

the opening is formed as an annular opening continuous over the entire circumference and is not opened to both front and rear ends in the sliding direction of the circumferential wall.

3. The roller lifter of claim 2, wherein,

the sliding surfaces are disposed at both front and rear end portions of the outer periphery of the peripheral wall in the sliding direction, and the opening portion opens into a recess portion that is recessed radially inward between the front and rear sliding surfaces.

4. The roller lifter of claim 1, wherein,

the rotation stopper is bulged continuously from a part of the peripheral wall.

5. The roller lifter of claim 1, wherein,

when the rotation stopper is projected in a radial direction on the peripheral wall, the entire projection area of the rotation stopper is contained inside the opening.

6. A method of manufacturing a roller lifter according to any one of claims 1 to 5, characterized in that,

when the rotation stopper is formed, a punch member for forming the rotation stopper, which moves in the radial direction, penetrates the opening portion and enters the inside of the peripheral wall, and pushes out a part of the peripheral wall to the outside.

7. The method of manufacturing a roller lifter according to claim 6,

a receiving die having a window is inserted into the peripheral wall and is disposed so as to abut against the inner peripheral surface of the peripheral wall,

next, the opening portion is formed by inserting a punch member for forming the opening portion, which moves in the radial direction, into the window portion of the receiving die through the peripheral wall and guiding the punch member.